一种可用于光声成像的产气脂质纳米粒的研究

目的 研制一种可生物降解,其产物可完全排除机体的材料用于光声成像。方法 应用肉眼、光镜、电镜、激光粒径仪检测纳米粒物理特性;应用光声成像仪、红外光谱仪探讨纳米粒光声成像机制;应用光声成像仪检测纳米粒在体外、体内成像效果及安全性。结果 肉眼观察纳米粒透明乳状,无分层,分布均匀,粒径(230.9±54.58)nm,电位(-22.8±5.75)mv,稳定性较好。二氧化碳可能是纳米粒产生光声信号原因。纳米粒光声信号随浓度、温度、时间增加而增强、面积增大;体外激光辐照对细胞无损伤作用。在体内,经鼠尾静脉注入纳米粒各组正常裸鼠血氨浓度均较对照组升高(P<0.05),但精神体征与对照组无明显改变;肿瘤局部出现光声信号在4小时达到高峰,随后逐渐消失。激光能量对皮肤及皮下组织无损伤作用。结论 碳酸氢铵脂质纳米粒可用于光声成像,且是安全、有效、价廉、无副作用的。     

一种产气超声/光声双模态纳米粒的制备及性质检测

目的 研制一种包碳酸氢铵溶液的脂质纳米粒,并观察其超声/光声成像效果。方法 采用薄膜水化法加挤出法制备脂质包裹碳酸氢铵溶液的纳米粒,光镜、电镜、激光粒径仪和电位检测仪检测纳米粒一般物理特性,并通过光声成像仪观察其超声/光声成像效果。结果 制备的纳米粒呈圆球形,形态规则,大小分布均匀,无明显聚集,平均粒径为(230.90±54.58)nm,电位为(-22.81±5.75)mV。碳酸氢铵纳米粒有超声/光声信号,双蒸水纳米粒无超声/光声信号。结论 成功制备包碳酸氢铵溶液脂质纳米粒,可用于超声及光声成像,为进一步体外、体内成像实验奠定了基础。     

Gas-generating polymeric microspheres for long-term and continuous in vivo ultrasound imaging

Ultrasound (US) imaging is one of the most common biomedical imaging methods, due to the easy assessment and noninvasive way. For more precise and accurate US imaging, many contrast agents have been developed in a form of microbubbles composed of inner gas and shell materials. However, microbubbles showed undesirable short half-life under acoustic field during US imaging and insufficient in vivo stability in blood flow due to diffusion or bubble destruction. Therefore, the improvement of the half-life and stability of microbubbles under in vivo condition is highly needed for long-term in vivo US imaging. Herein, we developed rationally designed gas-generating polymeric microsphere (GGPM) that can produce microbubbles without encapsulation of gas for long-term and continuous US imaging. The poly(cholesteryl γ-butyrolactone-b-propylene oxide), poly(CB-PO), with carbonate side chains was synthesized as gas-generating polymer by ring-opening polymerization of cholestryl γ-butyrolactone (CB) and propylene oxide (PO). As optimal structure for intense US signal generation, porous GGPMs (p-GGPMs) with the average size about 3-5 μm were prepared with poly(CB-PO) by double emulsion method. These p-GGPMs generated continuous US signals over 70 min, while the signals from Sonovue^®, a commercial US contrast agent were completely attenuated within 15 min. This long-term signal duration of p-GGPM was also reproduced when they were subcutaneously injected under the skin of mouse. Moreover, as advanced in vivo application, the fine US imaging of heart in rat was enabled by intravenous injection of p-GGPM. Therefore, these overall results showed the great potential of p-GGPM as gas-generating US contrast agent for in vivo biomedical imaging and diagnosis.